1. Field of the Invention
The present invention relates to a silver halide photographic material and a method for forming an image by developing the material, and particularly relates to a monochrome photographic material involving the use of dye images which can be processed with a color developer substantially free from benzyl alcohol, has a photographic property that is less deteriorated by a toxic gas such as formaldehyde, has an improved sensitization and fog with time, and relates to a method for forming an image.
2. Description of the Related Art
Monochrome images are developed from conventional silver images using a monochrome developing agent such as hydroquinone. There is a few laboratories and photo studios where such development can be conducted. Color paper is generally developed with a color developer substantially free of benzyl alcohol. A treating machine suitable for the color development is widely used in the laboratories and photo studios. It is desirable that a material for forming the monochrome images is applied to the color development.
It is known that a photographic system of forming the monochrome images utilizing a combination of cyan, magenta and yellow dyes (see, for example, WO 93/12465 corresponding to U.S. Pat. No. 5,362,616 and JP-A No. 6-505580). In the system, dyes are formed from a mixture of cyan, magenta and yellow couplers during the development. When reacting with an oxidized color developing agent, the couplers produce a neutral (black-and-white) image.
Recently, furniture and building materials reformed by formaldehyde, adhesives utilized formaldehyde as a curing agent, formaldehyde resin manufactured products, leather tanned by formaldehyde, clothing used formaldehyde as a bactericide and a bleaching agent are widely used. There are many chances that the photographic materials are contacted with a formaldehyde gas.
The present inventors discovered that a magenta coupler is affected by the formaldehyde gas even in a photographic system where a combination of a cyan dye, a magenta dye and a yellow dye is used to form a monochrome image. For example, if the above-described photographic materials are stored in a cassette made of a formalin resin, photographic properties are degraded by the formalin.
The present inventors discovered that a formalin scavenger is used to improve the degradation. However, the present inventors also found that the formalin scavenger sensitizes a portion of the photographic materials contacted with air, for example, an outermost surface or a side rim of a roll-shaped photographic material. Such phenomenon destroys an image balance upon exposure and development of the photographic material and is therefore not preferable.
An object of the present invention is to provide a silver halide photographic material for obtaining a monochrome image with a dye image where a magenta coupler is less affected by the formaldehyde gas.
Another object of the present invention is to provide a silver halide photographic material preventing sensitizing of a portion contacted with air for a while and decreasing fog.
Still another object of the present invention is to provide a method for forming a monochrome image with a dye image by developing it with a color developer substantially free of benzyl alcohol.